Street-network Sprawl in Agbor, Nigeria

What is Street-network sprawl?

Street-network Sprawl is a way to measure urban sprawl, worldwide, through the connectedness of the streets. Less sprawl means more connected, more walkable streets. Well-connected streets – like New York City’s grid – are more walkable and can be served by public transit.

The street network is permanent, and its connectivity affects the livability and environmental footprint of cities for decades and centuries to come. In places with more connected streets, residents drive less and walk more. A well-connected street network is associated with better outcomes for health, the environment, sustainable consumption, social integration, and equity.

We can quantify how connected street networks are with the Street Network Disconnectedness Index (SNDi).

SNDi -- our measure of street-network sprawl (disconnectedness)

The SNDi is a comprehensive measurement of “sprawl”. It captures:

A higher SNDi means less-connected streets – i.e., more sprawl. For the 10137 cities in our dataset, the average SNDi is 2.25, with half of the cities' SNDis falling between 1.08 and 3.25.

More information on the sprawl index can be found in these research papers:

To see the state of street-network sprawl across the globe, visit the sprawlmap.

Agbor: city in Delta, Nigeria

What exactly constitutes the spatial extent of the city? For these aggregations, we used the Global Human Settlement Layer Urban Center Database (GHS-UCDB) to define the boundaries of the city. These cities -- or urban centers -- cover areas that are densely populated and built-up, and so may extend beyond the spatial borders of these cities that we may be familiar with. The GHS area is shaded in blue.

View Agbor, Nigeria on the sprawlmap

Most recent snapshot: Taking into account the entire (i.e. aggregate) street network in Agbor as of 2014, the overall level of street-network sprawl is 2.51, which is in the 40th to 60th percentile of disconnectedness.

Trends in street network construction: The SNDis of street construction for the respective time periods are 1.1, 1.44, 3.46 and 4.53. In each period, new street development in Agbor steadily grows more disconnected than in the last.

Quantity of street network construction: The street network in Agbor spans a total of 365 kilometers. The period with the greatest volume of street construction was 1991-2000. These roads have an SNDi of 3.46, which is highly disconnected.

Effect on the aggregate network: New construction in each period adds to the total stock of streets, but does not change streets that have already been built. Therefore, it has a limited effect on the street network as a whole. The SNDis of the aggregate street network in the respective time periods are 1.1, 1.31, 2.14 and 2.51. Overall, the SNDi of the aggregate street network has risen: the street network in Agbor has become more disconnected.

Agbor and Delta do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Agbor rose steadily, while the SNDi of street constructions in Delta followed a zig-zag trend with an overall increase.

How do development practices in Agbor fare in comparison to others in Delta? Most recently in 2001-2014, street construction in Agbor was the 11th-most disconnected out of the 16 cities in Delta. Its position in the ranks since 1975 has risen; relative to other cities in Delta, street construction in Agbor has become more disconnected. Agbor ranked 13th in 1975, 13th in 1976-1990, 9th in 1991-2000 and 11th in 2001-2014.

Agbor and Nigeria do not follow the same trend in the disconnectivity of their street network constructions. The SNDi in Agbor rose steadily, while the SNDi of street constructions in Nigeria peaked in 1991-2000.

How do development practices in Agbor fare in comparison to others in Nigeria? Most recently in 2001-2014, street construction in Agbor was the 97th-most disconnected out of the 411 cities in Nigeria. Its position in the ranks since 1975 has risen; relative to other cities in Nigeria, street construction in Agbor has become more disconnected. Agbor ranked 137th in 1975, 201st in 1976-1990, 111th in 1991-2000 and 97th in 2001-2014.

Agbor and Delta do not follow the same trend in the disconnectivity of their aggregate street networks. The SNDi in Agbor rose steadily, while the SNDi of street constructions in Delta followed a zig-zag trend with an overall increase.

To date, Agbor is the 13th-most disconnected out of the 16 cities in Delta. Its position in the ranks since 1975 has not changed. Agbor ranked 13th in 1975, 13th in 1976-1990, 12th in 1991-2000 and 13th in 2001-2014.

Agbor and Nigeria follow the same trend in the disconnectivity of their aggregate street networks. The SNDi for both of these rose steadily.

To date, Agbor is the 159th-most disconnected out of the 411 cities in Nigeria. Its position in the ranks since 1975 has fallen; relative to other cities in Nigeria, the street network in Agbor has become more connected. Agbor ranked 137th in 1975, 200th in 1976-1990, 156th in 1991-2000 and 159th in 2001-2014.

As of 2015, Agbor had a built-up area of 16.63 square kilometers, and a population of 170519 people.

These are some other cities with approximately the same population: